Drier



Dec. 2l 1926.

G. HILGENBERG DRIER 2 Sheetsheet 1 Filed June 17. 192,5

Dec. 21 1926.

, G. HILGENBERG DRIER Filed Jun 17, 192s Fly.;

2 Sheets-Sheet 2 Patented Dec. 21, 1926.

UNITED STATES PATENTOFFIC.

GUSTAV HILGENBERG, OF HANOVER-BADENSTEDT, GERMANY.

DRIER.

Application filed. June 17, 1926, Serial No. 116,712, and in GermanyDecember 29, 1924.

This invention has reference to substantally drum shaped rotary dryingdevices and it is particularly adapted for the drying of granularmaterial, such as salt from salterns or salt-works, crystal-sugar, alumand the like, and among other important advantages it provides means ofsubstantially avoiding the destruction or injuring of the configurationand outer appearance of the material, and the overheating anddiscoloration thereof. Material of the kind referred to and similargoods are to be dried slowly, and at comparatively low temperature andwith as little mechanical handling as possible, so as to retain thepurity and the nice crystallized shape of the material. With this end inview so-called plate driers have been disclosed in the previous art inwhich the material is distributed on coaxially and spacedly superimposedannular surfaces, the .so-called plates or dishes, arranged to revolveon a vertical shaft and cooperating with relatively stationary Scrapersor wipers adapted to cause the material to travel con- V tinuously fromthe top to the bottom plate and through the entire system of plates ordishes. Such coaxially disposed annular surfaces are ordinarilyarranged, so as to retain a certain radial distance from the axis of thedevice, inasmuch as the rotary speed of the plates or dishes should becomparatively low, while their longitudinal extension should becomparatively large. If in such devices the surfaces of the plates wouldbe made to reach up to the shaft, the revolvingl speed adjacent theshaft would be much too low, and it would be impossible to arrive at' asufficiently long travelling passage for the drying of the material atthose points situated adjacent the rotary shaft of the device. In viewthereof it was customary to arrange a free vertical cylindrical spacebetween the drying section proper containing the revolving dryingsurfaces andthe shaft, this space containing merely the connecting meansbetween the shaft and the circulating or revolving plate surfaces, butbeingotherwise not utilized.

Now, my invention is distinguished by the is made to constitute a closedheating channel which is connected at its bottom to the admission meansfor the heating agent, while at its top it is connected to the eductingpassage.

The invention will be more particularly fact that the centralcylindrical shaft space described with reference to theaccompanyyingdiawing showing byk way of exemplification a form ofembodiment of the principles of the invention in Figure 1in verticallongitudinal section, and in Figure 2 in horizontal section. Figure 3 isa modied construction shown in vertical longitudinal section.

In the drawing f are the otherwise wellknown substantially annularplates or dishes, adapted for slow rotary movement on the verticalcentral axis; they are spacedly superimposed and may be staggering-lyarranged. They are disposed in an annular or cylindrical casing, asappears from the drawing. 1n the exemplification illustrated the outerwall of theV casing is immovable, and the interior wall of the casing isconnected by suitable struts, stays or the like to the shaft, and uponthe outer surface of the interior wall of the casing the plates ordishes f are disposed. cl are tightening means, sealing means or thelike of any well-known or other construction at those places where therelatively stationary Wall of the casing is connected to the rotatablewall thereof.

The heating agent is introduced from below and from a stationary channela into the central tubular space I), and it is laterally conducted awayfrom the top of the centr-al space by means of a channel c adjacent theouter surface of the drying room through which the heating gases aremade to descend. y

The direct heating of the drying material itself may be effected in theusual manner by causing hot'air to flow through the annular casingeither in the equal current or in thecounter-current direction asindicated in Figure 3 of the drawing in which the full-lined arrows Hshow the course of the drying iuid in the counter-current direction withrelation to the descending material under treatment, while. thebroken-line arrows G indicate both the downward movement of suchmaterial as well as the alternative flowingof the drying fluid in theequal direction. The openings n and n provided in the annular casingserve forv the charging and the escape of the material, and may also beutilized for the purpose of causing heating fluid to flow through thesaid annular space.

The material to be dried is introduced from the ytop into the casing,and it is removed froin the bottom of the casing. The material may bepushed forward along the individual plates and from one plate to theotherl by means ot wipers or scrapers g indicated in the drawing' andot' any suitable size and construction. The relative arrangement,position and shape ot' the dishes or plates is immaterial and maybe ofany desired kind, beine' mainly governed by the particular kind andcondition of the material under treatment.

In the preferred construction the heating agent passes from the tine orchannel a upwards into `the central shaft space b. Inasmuch as thisspace is of relatively large cross section, the heating gases arecausedto slowly ascend therein, so as to e'fiiciently transmit their heat tothe interior casing wall which carriesthe plates j and is rotated withthem. By this means the heat is retained and condensed in the center ofthe dcvice and is only allowed to spread on all sides in the radialdirection, and a Very superior utilization of the heat is therebyobtained as compared with other suggestions en'iploying exteriorheating. AIn view of the fact that plate driers ot'lthis general typeare usually constructed of large dimensions the heating of the devicemeans of a central shaft constitutes moreover a very important saving'ot material, and in this arrangement the heating gases atter leavingvthe Acentral heating' space may be caused to (iow along'w the outersurface, bathing the same and thereby increasing tli'e direct heating`surface by suitably shaping' and ai'- ranging' the channel c, withoutthereby in any way interfering with the easy accessibility trom withoutof the drying room.

The rotary interior shell of the casing encompassing the heating' 'flueZ1 may be ina'de of corrugated sheet metal with the corrugationshorizontally directed as shown at T in ll`igure 3 o'l the drawing'whereby tlie advantage is obtained that thehe'ating surface isincreased, while the Vrigidity or' the shell and of the entire casing isalso augmented. Furthermore, the 4central heating' space Z) may containguiding' or abutting` ii'ieaiis of any suitable vconstruction andarrangeiiiei'it and indicated diagi'an'imatically at IV in Figure l olfthe drawing', such `tor instance as altei'natine'ly 0i" staggeringlyarranged horizontal walls, partitions or sheet metal plates or the like,so as to suitably increase the path of 'the heating' lgases.

The fuel employed lor heating' purposes may be ot any desired kind.Heating gases or heated air from any suitable source of heat may be'caused 'to iow through the centrally disposed heating' sp Ace orspecial heating' bodies may be provided in this central channel or inthe channel a, as shown :it K in Figure 3 ol the drawing'. It is evidentthat various other means may be employed l'or the purpose ofintroducing' the hcatinc' iluid into the space 7);

The outer surfaces of the drying device may be protected againstradiation o'l'I heat by suitable heat insulating and protectingl meansshown at S as a coating, of ielt, asbestos or the like in Figure 3 ofthe drawing, and the metal and other parts may be covered with aheat-resisting coating of paint.

An additional current of air or the like may be led through the drying'space, so as to carry away the vapors and to assist in the drying'operation, such air current or tlielike being passed through theopenings n, a', Figure 3, in the same manner as above outlined withre'lerence 'to the rcirculation of heating' 'fiuid through such space.

ly means ot the construction according' to this invention a verythorough utilization or heat and a very uniform distribution ot the heatand of the material with a very important saving,` o't constructionalmaterial may be realized, so that important advantages will result tromthe new methods of drying according to this invention in which all thepartsoi: the material are subject to a certain translator-y motion o1"their own combined with a high degree ot heating efficiency.

lVhile I have described my invention b V way ot illustration withreference to a certain manner oi embodiment, I am not rcstrictcdthereto, and may employ diiierent changes and modifications inconnection therewith; thus I may cause the heating' ,frases to enter thedevice in the downward direction oi' l may make other changes in thearrangement and construction and operation ot parts without deviatingtrom the spirit and scope o't' the invei'ition, except as hereinafterspecified and stated in the appended claims.

1. In a drying device in combination a cylindrical interim' heating`chamber and an outer cylindrical casing', spacedly surrounding' theinterior chamber and rotatable with relation to each other, andsupporting means for the material under treatment, spacedlysupei'in'nliosed in the annular space between the inner and outer casingand spacedly secure'c'i to the rotatable casing for rotation lidtherewith intern'iediate the inner and outer casings.

In a drying device in combination, a cylindrical interior heating'caninel and an outer cylindrical casing, sp'acedly surrounding' the sameand rotatable with relation to each other, supporting' means for thematerial to be treated, spac'etlly superimposed in the annular spacebetween the casings and secured to the inner casing', and an educ-tingchannel tor the heating' `ases adjacent the outer casingl andcoimnunicating with the interior casing'.

3. In a drying' device in con'ibination, a cylindrical interior heatingcasing and an outer, substantially concentric cylindrical casing,spacedly surrounding,` the same, said casing-S being rotatable withrelation to each other, supporting means for the material undertreatment and staggeringly and epacedly superimposed in tlie annularspace between the casings and secured to one of said casing-s, and'wipingI means cooperating with the supporting' means.

Ll. ln a dryingl device in conibination, a cylindrical interior heating'casing and an outer, Subetantiall y concentric cylindrical casing,spacedly surrounding tlie saine, heat admitting means at the lower endot the in` terior casing, and lieat educting means at tlie outside oltthe outer casing and substantially adjacent tlie same and communicatingwith the top ot' the inner casing.

5. ',ln a drying device in combination. a

posed in the annular space between the casings and spacedly secured tothe interior` walls oi said space.

(i. ln a dryingdevice `in combination, a cylindrical interior heatingcasing, an outer cylindrical caeing, epacedly and concentricallysurrounding tlie saine and rotatable with relation toeacli other, andsupporting means for the material in the annular Space between thecasings and superimposedly fasvtened to the interior walls of saidspace.

GUSTAV HILGENBERG.

